Am.  Jour.  Pharm. 
Sept.,  1889. 
Division  of  Powders. 
465 
stantly  being  disengaged  from  the  unstable  carbonate  unites  with  the 
free  iodine  present  to  form  iodide  of  ammonium,  and,  as  the  super- 
fluous ammonia  is  subsequently  allowed  to  escape,  there  is  no  resulting 
contamination  with  a  foreign  substance. 
I  usually  remove  the  iodide  to  a  large  salt-mouth  bottle,  wrap  a 
vitreous  piece  of  ammonium  carbonate  in  filter  paper,  drop  it  into  the 
bottle,  stopper  tightly  and  place  aside  until  the  desired  change  has 
been  effected.  Then  remove  the  ammonium  carbonate,  leave  the  bottle 
unstopped  until  the  excess  of  ammonium  has  disappeared,  when  the 
salt  is  practically  pure  and  ready  for  use. 
DIVISION  OF  POWDERS. 
By  Hans  M.  Wilder. 
Mr,  Wiegand  concludes  his  article  on  the  above  subject  (p.  386)  by 
saying  that  "when  odd  numbers,  such  as  13,  17  or  19  are  ordered, 
the  best  plan  is  to  weigh  off  the  13th,  17th  or  19th  of  the  whole 
weight,"  and  then  advises  to  divide  the  remainder  by  the  parallelo- 
gram plan.  Now,  why  does  Mr.  Wiegand  not  go  on  a  step  farther, 
and  advise  to  divide  the  powders  by  weight,  all  of  them,  as  the  Ger- 
mans do,  instead  of  only  that  odd  part  ?  The  only  objection  that 
can  reasonably  be  made  is  that  it  would  take  more  time  than  could 
well  be  spared  in  the  rush  of  business,  etc.  This  idea  of  "more 
time,"  however,  is  much  exaggerated.  In  Germany,  for  instance, 
where  a  good  many  more  prescriptions  are  put  up  by  the  individual 
pharmacist  than  here  (except  in  hospitals  and  similar  institutions), 
the  pharmacists  get  through  pretty  quickly,  notwithstanding  that  pre- 
scriptions calling  for  24  or  48  powders  are  no  rarity,  in  spite  of  hav- 
ing to  weigh  each  powder  separately.  The  writer  has  for  months 
together  had  to  put  up  from  70  to  100  prescriptions  a  day  entirely 
unassisted,  and  often  had  a  dozen  or  more  prescriptions  at  a  time 
waiting  for  him,  still  he  managed  to  finish  within  a  reasonable  time  j 
of  course,  without  some  kind  of  a  system  it  would  have  been  impos- 
sible to  do  so. 
Now  as  to  the  division  of  powders :  The  parallelogram  plan  is  a 
decided  improvement  on  the  "guess-by-eye,"  but  weighing  each 
powder  separately  is  still  more  accurate ;  what  little  time  more  there 
may  have  been  used  is  balanced  by  the  satisfaction  of .  knowing  that 
